1. Field of the Invention
The present invention relates to heat sink assemblies, and particularly to a heat sink assembly having a fixing device for readily and firmly attaching a fan thereto.
2. Prior Art
Developments in today""s highly information-intensive society have led to remarkable improvements in performances of electronic devices. During operation of many contemporary electronic devices such as CPUs, large amounts of heat are produced. Such heat must be quickly removed from the electronic device, to prevent the device from becoming unstable or being damaged. Typically, a heat sink together with a fan is attached to an outer surface of the device to facilitate removal of heat therefrom.
Referring to FIG. 4, a conventional heat dissipating assembly comprises a heat sink 200, a fan 300, and a fixing device 100 for attaching the fan 300 to the heat sink 200. The heat sink 200 has a base 210, and a plurality of fins 220 extending upwardly therefrom. A pair of threaded holes 230 is defined in each of opposite side faces of the base 210. The fixing device 100 comprises a frame 120, a pair of legs 140 depending from each of opposite sides of the frame 120, and four locking posts 110 extending upwardly from four corners of the frame 120. An aperture 150 is defined in a distal end of each leg 140, corresponding to one of the threaded holes 230 of the heat sink 200. A screw 250 is extended through each aperture 150 of the fixing device 100 and engaged in a corresponding threaded hole 230 of the heat sink 200, thereby attaching the fixing device 100 to the heat sink 200. Crisscrossed slots 160 are defined in a top portion of each post 110, for providing elastic deformability. Four through holes 320 are defined in four corners of the fan 300. In assembly, the top portions of the posts 110 are resiliently extended through the through holes 320 of the fan 300. Once the top portions protrude from a top of the fan 300, they resiliently expand back to their original orientations. The fan 300 is thereby attached to the heat sink 200 by the fixing device 100.
However, the fixing device 100 and the heat sink 200 are two separate parts. The fixing device 100 must be attached to the heat sink 200 with numerous screws 250, which makes the assembly process unduly complicated and cumbersome. Furthermore, in operation, the screws are prone to be loosened by vibration and create noise.
An improved means of securing a fan to a heat sink which overcomes the above problems is desired.
Accordingly, an object of the present invention is to provide a heat sink assembly having a fixing device which firmly and reliably attaches a fan thereto.
Another object of the present invention is to provide a heat sink assembly which is easily assembled and thus lowers costs.
To achieve the above-mentioned objects, a heat sink assembly of the present invention comprises a fixing device, a fin member and a fan. The fixing device is integrally formed by extruding aluminum. The fixing device comprises a base, two side plates extending upwardly from opposite sides of the base, and an upper plate connecting the side plates and being parallel to the base, thereby defining a space therebetween accommodating the fin member. Four threaded holes are defined in four corners of the upper plate of the fixing device. The fin member is formed by continually bending a metal sheet to yield a concertina-like structure. The fan is box-shaped, and has four through holes defined in four corners thereof. Four screws extend through the through holes of the fan and engage in the threaded holes of the fixing device, thereby attaching the fan to the fixing device.
Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of preferred embodiments of the present invention with the attached drawings, in which: